Determine the Angle Between the Diagonal of a Cube and the Diagonal

Multiple Choice

Determine the angle between the diagonal of a cube and the diagonal of its base,as shown in the figure,where $a = 12$ .Round your answer to one decimal place.? ?

A) 38.3^o
B) 36.3^o
C) 39.3^o
D) 35.3^o
E) 37.3^o